It is the objective of this research project 1) to access the degree of depression among a sample of heroin addicts on methadone maintenance, 2) to attempt to relieve that depression by the administration of antidepressant drugs, and 3) to evaluate the effect of the administration of antidepressants on social adjustment and drug program treatment progress. These objectives will be met by utilizing standard self-report tests to measure depression and treatment progress and measuring the level of antidepressants in the blood.